Kornfeld and Bach, U.S. Pat. No. 4,198,415, disclose and claim trans-(.+-.)-5-permissibly substituted-4,4a,5,6,7,8,8a,9-octahydro-1H-pyrazolo-[3,4-g]quinolines and their tautomers, the corresponding 2H derivatives (I and II below), useful as dopamine D-2 agonists. ##STR1##
Each tautomeric trans-(.+-.) racemate consists of two enantiomers, the 4aR,8aR and 4aS,8aS derivatives. These four enantiomers are pictured below--Ia and Ib for the 1H tautomers; IIa and IIb for the 2H tautomers. ##STR2##
The copending application of Titus and Kornfeld, Ser. No. 439,238, filed 11/3/82, discloses a method of separating the tautomer pair I and II into their respective enantiomers (Ia and Ib or IIa and IIb) when R is n-propyl. Alternatively, the final tautomeric enantiomers can be prepared from an optically-active intermediate, a 4aR,8aR-1-C.sub.1-3 straight-chain alkyl or allyl-6-oxodecahydroquinoline (III) or a 4aS,8aS enantiomer (IV). The copending application of Schaus and Booher, Ser. No. 639,107, also filed 11/3/82, separates trans-(.+-.)-1-C.sub.1-3 straight-chain alkyl or allyl (specifically n-propyl)-6-oxodecahydroquinoline into these enantiomers ##STR3## where R is C.sub.1-3 straight-chain alkyl or allyl.
Reaction of III with the dimethylacetal of dimethylformamide or with tris dimethylaminomethane forms a 7-dimethylaminomethylene derivative, reaction of which with NH.sub.2 NH.sub.2 yields the tautomeric enantiomer, Ia.revreaction.IIa.
The tautomeric pair Ia.revreaction.IIa has been found to be useful in treating both hypertension and sexual dysfunction in mammals, see Hahn et al, J.P.E.T, 224, 206 (1982) and the copending application of Foreman, Ser. No. 518,906, filed 8/1/83.
The metabolism of the enantiomeric tautomers, Ia.revreaction.IIa, in mammals has not hitherto been disclosed nor have ring-oxygenated derivatives of trans-(.+-.)-5-permissibly-substituted-4,4a,5,6,7,8,8a,9-octahydro-1H(and 2H)-pyrazolo[3,4-g]quinolines.